In the context of improving the sealing of vehicles, new standards are being prepared, under the name EURO 2000, and they are going to lead to modifications and improvements of sealing.
For fuel tanks, several manufacturers have been directing their attention to O-rings for use as plug gaskets.
However, the use of such gaskets leads to two types of problems, in particular with tanks having a tank body made of a plastics material, e.g. polyethylene:
a) the tolerances on parts made of plastics material lead to gaskets having a diameter of at least about 5 mm, and this gives rise to the problem of bulk for housing the gasket, and to a problem of the neck of the tank being deformed; and PA1 b) there is exists the problem of holding the gasket against the rim of the tank prior to putting the plug into place.
Certain vehicles are fitted with plug gaskets that have lips which perform a function of taking up clearance at the price of greater complication with respect to the profile of the gasket, and in particular with respect to molding it.